D2D communication refers to a communication mode between a pair of user equipments (UEs) that enables a UE to directly communicate and exchange data with a neighboring UE without the help of a cellular network, and each UE for D2D communication (hereinafter referred to as “D2D UE”) broadcasts the UE's own information in order to inform other UEs of information on itself. A UE's own information used to inform other UEs of information on itself may include, for example, the identifier (ID) of the UE or the ID of UE's user (hereinafter referred to as “proximity service ID”, “ProSe ID”, or “D2D ID”). In addition, a UE acquires information on counterpart UEs through expressions received from neighboring UEs, and attempts to perform D2D communication when discovering a counterpart UE of interest from this information.
Communication providers try to make a profit by providing D2D communication by using their underused licensed spectra or using unallocated radio resources in cellular networks and the like. Thus, they are seeking a way to provide D2D communication and control D2D services, based on a cellular network.
Therefore, there is a need for a way to detect an ID, allocated in a cellular network (e.g., GUTI (Globally Unique Temporary UE Identity), from the ID of a UE or the ID of a UE's user (e.g., ProSe ID), used in D2D communication, in order to control paging and the like of the corresponding UE in the cellular network.